


a bad case of the wilds

by kaistrex (weishen)



Series: Prompts [20]
Category: Teen Wolf (TV)
Genre: Alpha Derek, Anal Sex, Blow Jobs, Canon Universe, Come Inflation, First Time, Fluff, Fluff and Smut, Loss of Virginity, M/M, Mates, Plot What Plot/Porn Without Plot, Porn with Feelings, Semi-Public Sex, Smut, Summer, Virgin Stiles Stilinski
Language: English
Status: Completed
Published: 2021-02-14
Updated: 2021-02-14
Packaged: 2021-03-15 08:02:28
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 6,446
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29432859
Author URL: https://archiveofourown.org/users/weishen/pseuds/kaistrex
Summary: “I could smell you all over town,” Derek growls.Stiles squints back at him, trying to parse what Derek wants from him with that statement. An apology?“Okay?” he says instead, which, as with everything else he says around Derek, seems to be the entirely wrong thing to come out of his mouth.Derek’s eyes go red and Stiles bolts upright in his chair, trying to scoot backwards, banging into his desk.“Dude, what the fuck?”“Get away from me, Stiles,” Derek bites out, hands clenched into fists.Stiles rolls his head on his shoulders. “Dude, this ismyroom. You get away from me.”–Basically, I wanted Derek fucking Stiles up against his bedroom window on a full moon with the blind up, so I wrote it. Happy Valentine's Day!
Relationships: Derek Hale/Stiles Stilinski
Series: Prompts [20]
Series URL: https://archiveofourown.org/series/523144
Comments: 40
Kudos: 697





	a bad case of the wilds

**Author's Note:**

> I can’t remember which side of the house Stiles’ window is on and didn’t really care to find out, but for the purposes of this fic, we’re pretending it faces onto the street. There’s no mention in the fic of anyone seeing them, so you can imagine it either way. (Stiles does express vague discomfort about being in the window at first, but is ultimately into it, just in case that squicks anyone!)
> 
> I did plan for this to be a straight pwp, but then feelings happened because I can’t not with these two.
> 
> Title taken from [Easy Tiger](https://www.youtube.com/watch?v=IxCoQovJysw) by Every Time I Die.

Stiles thinks he might be melting. He’s so hot, he’s sure that can’t just be sweat starting to trickle down the back of his neck. He swipes at it irritably, adjusting his shorts and tank top like that will do anything to help cool him down.

June has only just begun but it already feels like the height of July, the air the same ungodly temperature inside as it is out, no matter how wide he opens his window in an attempt for cooler air.

It wasn’t quite hot enough to stop him jerking off earlier though. Perhaps not his best idea, but he’s not sure any temperature could stop him doing that. It had been a little risky, but he’d kept the window open, blind up, for that precious whisper of breeze, but he made sure he was pressed back in the corner of his bed against the wall so he couldn’t be seen. He kept his mouth shut and any noises beyond the slide of his hand trapped away. It left him bonelessly sprawled on the bed but then he started sticking to the sheets and ended up perched on his desk chair instead.

He’s not doing anything but sitting there and lamenting how hot he is, wondering if it’s time to just set the shower to cold and camp out in there. That’s what he’d been doing for most of the day since he got home from school anyway, until his dad kicked him out so he could shower before work. Usually he’d be dicking around on his laptop, on a Wikipedia spiral or researching more about the supernatural or watching porn, but with this already sweltering heat, he doesn’t want to invite even more to come blasting into the room from the laptop fan. He’s just glad that there’s only a few more days of school until he’s free for the summer, to lock himself in the freezer and never come back out.

He tugs at the neck of his tank in an effort to fan himself when the _thunk_ of his window sliding shut has him leaping out of his skin. He manages to right himself on his chair and spin round to find Derek standing there, in his usual jeans and leather jacket like an absolute freak, and Stiles feels like his skin is igniting just looking at all those layers.

Derek speaks before Stiles gets a chance to ask what the hell he’s doing.

“I could smell you all over town,” he growls.

Stiles squints back at him, trying to parse what Derek wants from him with that statement. An apology?

“Okay?” he says instead, which, as with everything else he says around Derek, seems to be the entirely wrong thing to come out of his mouth.

Derek’s eyes go red and Stiles bolts upright in his chair, trying to scoot backwards, banging into his desk.

“Dude, what the fuck?”

“Get away from me, Stiles,” Derek bites out, hands clenched into fists.

Stiles rolls his head on his shoulders. “ _Dude_ , this is _my_ room. You get away from me.”

His eyes are simmering red now, glowing, all his canines lengthening, just like that time at the Sheriff’s station last year when he’d jumped in to roar at Isaac. But that’s an image Stiles doesn’t need to think about right now. He has to look away from Derek’s face, and his eyes land on the full moon outside instead.

“Are you okay? You’re not losing control because of the moon, are you?”

If yes, that’s kind of a terrifying prospect. He’s never known Derek to have any trouble on a full moon, born wolf and all that. Stiles is already thinking about hitting the books, finding some cure for whatever this affliction must be but—

Derek’s starting to look a little less agitated – though no less predatory – almost a smile on his face where he has Stiles pinned by his Alpha gaze, something eager.

“Stiles. I’m going to give you ten seconds.” Derek looks like he’s buzzing, barely-restrained energy, voice thick around his fangs. “You’ve got ten seconds to get out of this room, to get away from me, or I’m going to fuck you right here.”

Stiles’ mouth drops open. Derek’s gaze drops to his lips and he takes an aborted half-step forwards, breath rasping through his fangs.

Stiles manages to swallow, licking at dry lips. “What the hell are you talking about?”

Apparently, what Derek said was supposed to be self-explanatory because he just starts counting.

“Ten. Nine.”

“Wha—?” Stiles can’t do much more than blink at him.

“Eight. Seven.”

Derek’s taking a breath between each number, like he’s savouring the build-up, tasting it.

Stiles licks his lips again and swallows. This can’t be real. Derek’s just fucking with him. It’s the full moon addling his brain. He doesn’t really mean that he’s gonna…

“Six. Five.”

Either this is a joke, or it isn’t. If it is a joke and he runs, he’s going to give Derek something to really laugh about. If it’s not a joke and he runs, he’s going to miss out on the best thing that could have happened in his life so far.

“Four. Three.”

If it’s a joke and he stays, he gets to tell Derek he called his bluff and not give him the satisfaction of making the fragile human a punchline. If it’s not a joke and he stays… Yeah. Stiles isn’t fucking going anywhere.

“Two.”

Derek is advancing now, and even though the countdown isn’t yet over, Stiles knows the window to escape has already closed. It’s like the safety bar has just been lowered on a rollercoaster, the cart starting to creep along the track, about to make the _clickclickclick_ of its ascent. He just hopes it really does go up instead of rolling through a trick door to eject him at the exit.

“One.”

Derek is on him then and Stiles is being lifted out of his chair like he weighs no more than a kitten.

He squawks, arms flailing. “Derek, what—?”

He’s slammed against the window face first, just managing to turn his cheek in time to protect his nose. The glass is icy against his heated skin, fogging up where his open mouth pants against it, the cold and the friction against his nipples sending sparks down to his cock which is suddenly half-hard and starting to tent his shorts.

Wait—when the hell did Derek get his tank off?

“I told you to run.” Derek licks a wet trail up the side of his neck, growling, his red eyes reflecting back at him in the glass. He’s licking up Stiles’ sweat, tasting it.

This is really fucking happening. It wasn’t a joke. 

“Just can’t help yourself, can you?” Derek grits out, hands firm at his hips, the bite of his claws. “Always have to push back. Can never just do what I say.” His mouth presses to Stiles’ ear, a cascade of breath over his cheek. “Drives me crazy.”

Derek’s heat disappears from his back and Stiles makes a plaintive noise, but Derek is back in a second, after the sound of the drawer of Stiles’ nightstand opening. He glimpses something in Derek’s hand and his mouth drops open. That’s Stiles’ lube.

“How did you know where—”

“I know what you do to yourself when you’re alone. When your dad’s out.” Derek’s voice drops to a breath, back against his ear. “Heard you say my name.”

Stiles gasps. “Derek, I—”

He’d always been so careful. With the bane of werewolf hearing always at the forefront of his mind, he’s always made sure to never say anything out loud that could incriminate him. But he just got so deep into a fantasy once, forgetting where he was. He used too much lube, got so sloppy with it, dripping down the backs of his thighs as he rocked back on three of his fingers with his face in a pillow, ass up. He’d heard Peter make a comment once, about _inflation_ , and he fell down a rabbit hole of research until he’d confirmed that, yes, werewolf males come a whole lot more than human ones – especially born wolves. It became a fixation, an obsession. He’d never even been with a normal guy to know what that felt like dripping out of him, but his fantasies skipped straight over that and went to werewolf. To Derek.

So there he’d been, covered in lube and imagining it was Derek’s come, hot and slippery, imagining his fingers were Derek’s feeding the come back inside him whenever it tried to escape, imagined it was Derek’s cock spearing back inside to fill him up again, pump him full of another load—

And he’d come just like that, a choked off cry of Derek’s name into his pillow, his cock jerking his meagre human load untouched all over the sheets.

But that was—that was _months_ ago.

“You heard that?” Stiles asks weakly.

“What were you thinking about? What were you imagining that I was doing to you?” Derek sounds almost frenzied, like the curiosity has been eating him alive all this time.

Stiles doesn’t answer and he feels the pressure of Derek’s fingers against his throat. He’s not squeezing, not even close, but it’s the threat of it, the idea of it, and it has Stiles babbling after a gasp. His voice comes out strangled no matter that Derek’s fingers have no intent behind them.

“Your come. Was thinking about your come. Wanted you fucking it back inside me. Want it all. Please. _Please_.” He flails back with his hand to grasp at Derek’s bare hip – _fuck_ , he’s naked – and tries to pull them flush together, like that will somehow have Derek buried inside him. Then his mind catches up and he twists his head round, contorting. He wants to see— He _needs_ to see—

Derek’s cock is perfect, because of course it fucking is. Uncut, long, thick, a gentle curve upwards. But it’s his balls which Stiles eyes get drawn to, fat and round and heavy, and Stiles makes a sound in the back of his throat. He presses his cheek back to the window, panting again, the flash of cold sharpening his focus.

“ _Fuck_.”

Derek doesn’t waste Stiles’ moment of distraction. With one shove, Stiles’ shorts and boxers hit the floor and then he realises he’s standing completely naked lit up at the window of his bedroom. With the light behind his head, there’s no way anyone will be able to see it’s him. But that doesn’t change the fact that every single person on this street knows this is his room, so who else is it going to fucking be?

“W-w-wait,” he tries to protest, tries to push back.

But Derek crowds him against the glass so he can’t get away, pinning him in place with the weight of his chest. He’s pressed to the window from knees to cheek and he hisses at the flash of cold along the line of his cock, jerking his hips away. It makes his back curve in an obscene arch, popping his ass out, and Derek makes a noise of interest. His hips shift and then there’s Derek’s cock settling in the cleft of his ass, thrusting slowly back and forth. Stiles’ fingers scrabble at the glass, eyes wide, hands landing on either side of the window frame for purchase. The slide is still dry where Derek is rocking his hips and Stiles can feel the drag of his foreskin catching and pulling back.

A strange noise lodges in Stiles’ throat. He has no idea what it was supposed to be, but he feels a little like his mind is splitting, overwhelmed by every little point of contact between them, each of Derek’s fingertips, his chest hair against his back, the brush of his thick thighs, his cock. His cock, which is hard, because of _him_. This is Derek. Why is this Derek? Why is Derek _here_ , doing this with _Stiles_? Whatever the reason, Stiles is so fucking grateful.

The slide is getting wetter, Derek’s precome easing the way, and then something cold is drizzling over their heated skin and they’re both groaning. Derek’s hips speed up a little, spreading the lube between them, and Stiles moans and bites at his lip as the increase in speed makes his nipples drag against the glass. Faster still Derek thrusts, and then the head of Stiles’ cock is bouncing off the window with every forward jerk, little zings of icy pleasure, and he has the far-off thought that maybe this is what using ice cubes is like.

Derek’s impatience is ratcheting up, pulling back just too far, enough that the head catches on Stiles’ rim, skimming over the tight muscle, and Stiles’ eyes almost roll back. Derek’s cock presses against him there with intent, like Derek has taken himself in hand. Stiles’ eyes flutter shut at the image, of the flushed red head of Derek’s cock dwarfing the tight little furl of his hole, the knowledge that in a few minutes time that cock is going to be stretching him impossibly wide and filling him up in a way his fingers have never been able to before. He feels his hole flutter, like it’s trying to loosen up enough to be able to welcome Derek inside then and there. Derek growls at that, a low rumble deep in his chest.

Stiles turns his head the other way, chilling his other cheek for another flash of clarity. His skin slips against the window, just starting to fog up with their building body heat. But it’s enough to draw his brain back to the real problem at hand that Derek’s cock against his ass had distracted him from.

“Derek. _D-Derek_ , I’m _naked_.”

Derek chuckles and laps at Stiles’ neck again like that’s a fact that he’s very much enjoying – and, hey, Stiles’ isn’t gonna lie, that’s a pretty great feeling—but _focus!_

“We’re at the goddamn window! Someone’s gonna see!”

“Let them.” Derek says immediately. His voice deepens, perilous. “Let them see that you’re _mine_.”

And then Derek’s now-clawless finger is dragging through the mess of lube covering his ass and sliding straight inside him. Stiles’ spine stiffens, ass clenching down in shock, and a strangled _hng_ leaps out of his throat at having something to tighten around. His eyelids flutter and he really thinks he might just come. This is Derek. Derek _fucking_ Hale. With a finger in his ass. Naked in his bedroom. Together.

Stiles’ toes curl in the carpet, forehead against the glass now, chest heaving for breath.

The air has gone so fucking thin, all that summer heat locked in here with the heat getting churned out by their arousal. He’d been sticky with sweat before, but now it’s a sheen, all over him _and_ Derek. And Derek’s finger is still inside him. He knows Derek’s fingers aren’t quite as long as his own, had done little tests like gauge how far round Derek’s fingers had clasped when he picked up a bottle of water after a training session with his betas – acting like the creeper he always accuses Derek of being. They’re thicker though, like every single part of Derek, which he can definitely feel right now, somehow acutely, like every single nerve ending in his body is suddenly connected to the rim of his asshole. They’re not as long, he knows they aren’t, but this lone finger is somehow reaching a place even deeper inside than his own have ever been able to go.

Derek drags the digit back out to the tip and then thrusts it back in, and Stiles eyes snap open, throat squeezing out another moan, rising into a whine as he catches sight of a string of precome stretching out between the head of his cock and the window. He can see the moon, fat and full above their heads, which just makes him think of Derek’s balls, _fuck_.

He’s fucking ruined. No other sexual experience is ever going to come close to topping this and they haven’t even gotten to the main event. They’re not even past one finger.

Derek’s freakish werewolf senses must hear his thoughts somehow because he starts to work a second finger in beside the first, adding more lube, thrusting and thrusting and thrusting. It’s gentle compared to all of Derek’s other movements so far, taking his time, either to be careful with Stiles or, more likely, to enjoy the sight of Stiles’ ass opening up to take more and more of him. It seems to take an age, Derek’s fingers twisting and crooking and spreading until Stiles is crying out as they graze something deep inside him and is starting to bounce back on the thick digits. The tip of a third starts to join in then and the process starts all over again, stretching him wider than he’s ever been stretched before.

Stiles’ cock is dripping and he can’t take it anymore, lets go of the window frame to give himself a stroke, just one, something to take the edge off—

But Derek snatches his arm by the wrist and holds it back to the window.

“Please, Derek, _please_. Just give me something. Need something—”

“Soon,” Derek promises, and then he’s tucking the tip of his little finger in alongside the other three and Stiles’ knees are trembling, about to give out.

“Derek, I can’t, you’ve gotta—”

Derek growls, and then his fingers disappear from inside him, replaced in moments by the pressure of the blunt head of his cock. It—It feels _huge_.

“Okay. Okay okay okay,” Stiles mutters to himself as he breathes deep, psyching himself up. This is really happening.

Derek rubs the slick head of his cock against his entrance until Stiles relaxes enough that his clenching hole gapes back open, and then he's pressing inside him until the head of his cock pops past the tight ring of muscle. It punches the breath from Stiles’ lungs and pins him there, unable to focus on anything but the way Derek moves inside him, inch by careful inch, the fullness, pulling back only to press a little deeper. He has no idea how long it takes until Derek is fully-sheathed inside him, losing all sense of time and even where he is, until he feels the brush of the hair at the base of Derek's cock against his ass.

A broken sound spills from his lips, his throat going tight. Derek starts to move again but Stiles slaps at him.

“W-w-w-wait! I can’t—I can’t breathe.” It’s like Derek’s cock has taken up the space he needs for his lungs to expand for breath and the stifling heat in the room only works against him. 

“ _Shhh,”_ Derek murmurs at his ear, pressing his chest to Stiles’ back and a hand to the top of his stomach. Derek breathes deeply into his ear and Stiles follows the rhythm of his expanding chest at his back, the breath juddering back out of him on the exhale. The window is almost completely fogged at this point, the red pinpricks of Derek’s eyes cloudy in the dulled reflection. 

Again they breathe together, and then Derek is drawing his hips back and sliding back in deep and Stiles’ eyes glaze over.

“ _Derek."_ Even Stiles can hear how reverent he sounds, like having Derek’s cock inside him is a religious experience.

“So good for me, Stiles. So good taking your first cock.”

Stiles almost squirms. How the fuck is he supposed to cope with Derek saying shit like that? The fact that Derek knows he’s Stiles’ first has his skin flushing impossibly hotter, like he’s ready to ignite. The praise has Stiles arching his back, lifting his ass to give Derek better access, revelling in the slide and stretch with the slowly increasing strength of Derek’s thrusts. He loses himself in the movements, in the bounce of his heavy cock between his thighs, in and out, his laboured breaths rasping in his ears. 

“That’s it, baby,” Derek whispers, his fingers tweaking Stiles’ tight nipples, and Stiles gasps. His eyes flutter open where they’d fallen shut without him noticing, realising that it’s not Derek moving right now. It’s Stiles. Derek’s hands might be playing with his nipples but his hips are still, holding himself in place as Stiles rolls his hips back and fucks himself on Derek’s cock, while Derek just stands there and watches. Stiles’ hips stutter. How long has this been going on? What must he look like, moaning and writhing, totally gone on the feel of Derek’s cock inside him? His cheeks burn, and Derek’s arms come around him, tightening.

“It’s okay, baby. You don’t need to stop.” Derek’s hips start to rock again, coaxing Stiles to continue, but that endearment keeps playing in his mind over and over, the sudden tenderness making his head spin. 

“Derek, I-I can’t—”

“Yes, you can, Stiles. Just do what makes you feel good.”

Stiles pushes himself back again, meeting all of Derek's thrusts, their combined effort making the movements harder, more powerful, and after not even a minute, Stiles’ entire body starts to quiver, his knees going weak.

“Derek, I can’t—” he tries again, and this time, Derek must sense he’s reached his limit.

A hand hooks behind his right knee and lifts it up as high as it will go, and Stiles cries out, hands scrabbling at the glass again as he's spread wide, pulled up onto his tiptoes on his one foot still on the floor and sinking what feels like another two inches down Derek’s cock.

One hand ends up braced against the top of the window frame, the other reaching back to clutch at the back of Derek’s neck. He can’t do anything but relax into Derek’s immovable strength and take it, take every inch of Derek making a space inside him, let himself be used. His jaw is slack, no strength to keep it closed and bite down on a rising string of _ah ah ah ah_ getting punched out of him with every thrust. Derek growls and just fucks him harder, making Stiles’ eyes roll back. He needs something more to hold onto, his hand still on the window frame reaching back to grab at Derek too, tangling in his hair. 

He’s so exposed like this, the position of his arms making his back arch, cock jutting out so it starts to hit the window again. He’s dripping precome and it smears all over the glass with Derek’s thrusts. Then Derek’s hand wraps around his cock and Stiles knows it’s just seconds until this will all be over. 

One, two, three strokes and his body goes taut like a bowstring. He jerks in Derek’s grip with a sob, fucking forward into his fist and back onto his cock as every single spurt of his come streaks against the window. 

Derek growls again, frantic, his hips jerking erratically until he’s slamming inside one last time with a roar.

Stiles’ eyes glaze over on a keening whine, his cock dribbling out another pulse of come at the sensation of heat flooding inside him. Derek’s come. Derek’s inflated load of _werewolf_ come. 

“Oh, my God,” he whimpers. 

Derek is growling, one continuous sound rumbling in his chest as he circles his hips and keeps coming, lifting Stiles knee impossibly higher, like he’s trying to pump him full off every last drop as deep as he can possibly get it. 

Stiles’ neck goes limp and drops his head back on Derek’s shoulder, trying and failing to catch his breath. Derek licks him again, gathering his sweat on his tongue. 

Something tickles the inside of his thigh and he manages to lift his head to stare. Derek’s come is starting to ooze out around the base of his cock where he’s still deep inside, a rivulet starting to trickle down his leg still on the ground.

“Oh, my God,” he says again, this time a whisper.

With one last grind of his hips, Derek lowers Stiles’ other leg back down and then lifts him up to carry him to the bed, still connected. This is the part where Stiles kind of wishes the myth of knots was also true, to keep everything Derek just gave him locked inside. He hazily thinks about a plug, wishing he had one handy for this occasion. He supposes he won’t ever get a chance again.

He doesn’t think any explanation Derek gives could make sense of what just happened between them. What made Derek appear in his room? What had him so riled up? Stiles fucking prays this wasn’t some crazy fuck or die situation, that Derek really was in control of his faculties.

Derek lays them down, Stiles facing the wall with Derek pressed all along his back, still inside him but going down. He doesn’t even want to know what his sheets are going to look like in the morning. His lower back twinges and he won’t be surprised if he wakes up to a permanent kink in it after the way he’d been arched for the past who knows how long.

“Sleep,” Derek whispers, and Stiles is too exhausted to do anything else.

*

When he wakes up, the room is flooded by the grey-blue light of dawn. Derek is on his feet, standing at the window in all his naked glory and Stiles takes a moment to appreciate the magnificent ass he didn’t get to see last night. He marvels that Derek is still even here. He would have expected him to have slipped out while Stiles was still sleeping, leaving him to march over to Derek’s loft and force answers out of him somehow.

He looks softer in the dawn light, a sharp contrast to how he’d been last night under the pull of the full moon. Less animalistic. Back to regular levels.

Derek opens the window a few inches, finally letting in a welcome cool breeze, like the heat of the past few days has finally broken.

_I could smell you all over town._

Now the whole pack is going to know exactly what went down last night. 

“Are you leaving?” Stiles asks, voice quiet in the hush. Derek is still naked but Stiles is expecting him to gather his clothes and hop out of the window he’s just opened, to not even look at him. Derek comes back to the bed instead, climbing on with him and gathering him into his arms.

A car rumbles a few streets over, birds singing, most of the surrounding neighbourhood still asleep.

Stiles swallows, glad his face is hidden against his neck as he asks, “What was that?” He hates how fragile he sounds, how unsure. What happened last night was confusing to say the least.

Derek is quiet for a moment, his voice grave when he speaks. “A mistake.”

Stiles’ body jerks like he’s been stabbed right through the chest, and he slaps at Derek’s torso, shoving, rearing up in a sudden bout of fury, like he can’t stand to feel Derek’s touch against his skin, wants him out of here.

Derek grabs at his hands, anguish on his face as they finally look at each other. “I didn’t mean it like that.”

“Then what the hell did you mean?” Stiles’ voice has gone embarrassingly thick, the prick of wetness in his eyes as that initial stab turns to a miserable ache.

“You drive me crazy.”

Stiles stares back at him, full of suspicion.

“I would have chased and caught you last night no matter where you ran. All this time I—I’ve been holding back. I’ve been so careful.” He rubs a hand down his face. “And then one whiff of your scent. Your come and arousal on the breeze on a full moon.” He bites out a self-deprecating laugh. “That was all it took.”

Stiles is trembling, every word out of Derek’s mouth too much to take in. “Holding back, why?”

“You were sixteen when we met, Stiles. You’re only seventeen now.”

“For that long?” The way Derek talks, with that certainty. It can only mean one thing.

Derek avoids his gaze, like he’s said too much. “Keeping you at arm’s length was easier.”

Stiles had always thought Derek couldn’t stand him in the beginning, until it became grudging tolerance of Stiles’ unavoidable presence in his life. But that never explained how he’d always turn to Stiles whenever he needed help or how he’d always put protecting Stiles above his own wellbeing.

Stiles looks down at Derek’s arms around him now. “I can't go back to that.” He draws closer like he's scared Derek will thrust him back to arm’s length and keep him there, keeps his eyes on Derek’s face like this whole thing might slip through his fingers. 

Derek laughs darkly. “And you think I can?” His face softens as he looks up at Stiles hovering over him, and then his fingers are grazing Stiles’ cheek and his lips are brushing Stiles’ own. It’s gentle and tentative, in such stark contrast to the lust of last night and it steals Stiles’ breath.

He ends up on his back, Derek lazily coaxing his mouth open with his tongue and Stiles gladly lets him in.

“Can I taste you?” Derek breathes into the kiss, and Stiles is thinking he already is until Derek’s fingers loosely grasp his erection.

"O-oh, y-yeah, s-sure," he gasps out, unable to close his mouth as he watches Derek descend his body.

In a few strokes of Derek’s hand, he’s at full hardness, and then Derek’s tongue is darting out to lap at the head and Stiles is soon a shaking mess, fingers clamped over his mouth, a knuckle between his teeth.

He’s torn between wanting to watch every single moment of this and being unable to support his head, the soft, wet ring of Derek’s lips an almost hypnotic drag up and down, the gentle suction curling his toes and sending warmth shivering under his skin.

Derek is quiet as he explores Stiles cock, finds out what makes him whine (the barest graze of teeth), what makes his entire body vibrate like he’s being pumped with a thousand volts (digging the pointed tip of his tongue into his slit).

Stiles is gasping, conscious of the open window as he tries to contain his noises, but it soon grows to be too much.

“Derek, I’m gonna—”

Derek doesn’t stop, just keeps bobbing his head and working the base with his hand, and Stiles’ heaving breaths crescendo in a single cry as he comes down Derek’s throat. Every tensed muscle goes limp, head packed with cotton wool as his ears start to ring.

He gulps down air like he’d been drowning, blinking hard, only coming back to himself when Derek starts climbing up his body. He starts to reach for Derek’s cock, eager to return the favour, but Derek is still soft. Derek’s lips twitch with amusement at whatever expression is on Stiles’ face.

“I can’t go again that soon,” he says, blanketing Stiles’ body. “Normally, but not after a full moon.” He drags his nose along the line of Stiles’ jaw. “Not after everything I gave you.”

“ _Hng._ ”

Derek pulls back to stare at him with a raised eyebrow, and maybe the beginnings of a blush in his cheeks. “You really like the idea of my come that much?”

Stiles winces. “Maybe?”

Derek’s eyes glitter. “Then I’ll make sure not to waste a drop from now on.”

“ _Hng_ ,” Stiles says again at the promise, going boneless, much to Derek’s amusement. This is going to happen again. Many many many times.

He turns his face away, needing to breathe, and looks at the window instead. The light slanting in is starting to turn golden with the rising sun.

“I can’t believe you fucked me against the window.” He groans, rubbing at his face. “What if someone saw?”

“Yeah, that was another mistake,” Derek agrees, wryly, scratching at his stubble. “We might have a problem if some little old busybody across the street tells your dad it looked an awful lot like Derek Hale was pounding his son against his bedroom window last night.”

Stiles’ mouth goes dry at that, but not because of the mention of his dad finding out. _Pounding_ is exactly what Derek had been doing, splitting him open, so fucking deep.

Derek’s nostrils flare at a scent he must catch and he rubs a hand over his face. “ _Stiles_.”

“What?” he asks, innocently.

“You can’t keep getting like that when I can’t take care of you properly.”

“You took care of me pretty well with your mouth just now,” he points out with a shit-eating grin. He walks two fingers teasingly up Derek’s bare chest, aiming for nonchalance. “Do you have any idea when you will be able to take care of me ‘properly’?”

Derek tilts his head down to stare between his legs with a frown like he’s willing himself to get hard. He heaves a sigh and drops his head to Stiles’ shoulder in defeat.

Stiles laughs, almost a giggle, feeling lighter than air. “You really want me that much?”

Derek lifts his head to look at him. “I always want you,” he says flatly. “And now I get to have you, I can’t have you how I want.” He shakes his head. “Do you have any idea how close I got to breaking in here that time I heard you moan my name?” he asks, and Stiles’ brain short-circuits. “You were so wet. I could hear it. I could have just gotten behind you and slid straight in before you even realised I was in the room.”

Stiles eyes glaze over at that thought, that image, the way his mouth would have dropped open, eyes rolling back as that entire length sheathed inside him. Stiles whines. “I wouldn’t have stopped you.”

“You wouldn’t have been able to.”

Stiles’ heart skips a beat at that, Derek’s gaze flickering down to his chest, and he shakes his head. “No sense of danger,” he huffs. “I could have hurt you.”

Stiles rolls his eyes. “But you didn’t. You didn’t come in and you didn’t force yourself on me. Even earlier, you didn’t hurt me. You made sure I was ready and went slow and even stopped to help me breathe even though you probably wanted nothing more than to start pounding away.” Derek’s lips twitch at that, ducking his head. “I trust you. If you knew you were in any danger of hurting me, I know you’d stop.” He reaches up to tilt Derek’s face back up so he’s looking at him, stroking Derek’s cheek, frowning. “Give yourself more credit.”

Derek stares back at him, for some reason looking kind of amazed. He takes Stiles’ hand and kisses his fingertips, reverently.

“I’m just so relieved,” Stiles murmurs, watching each press of Derek’s lips. “I worried that—I don’t know. That you weren’t in control of yourself because of a spell. That maybe I’d used you against your will or something. That maybe I should have stopped you.”

“Like I said,” Derek says, wryly. “You wouldn’t have been able to.” He strokes Stiles’ cheek. “But no. No spell. Just my own lust.”

That word makes Stiles’ stomach swoop. How could he possibly be responsible for any sort of lust in anyone, let alone Derek? He turns his head to kiss Derek’s fingertips just as he’d done to him and Derek smiles, small and shy. He presses one gentle kiss to Stiles’ lips before rolling off of him and climbing from the bed.

“Come on. You need to get ready for school, and I need to get out of here before your dad gets home.”

Stiles groans at the mention of school, stretching out to the full length of the bed in a mini tantrum. How is he supposed to walk after what happened last night? He also needs to shower, urgently.

He reaches out with his leg to nudge at Derek’s ass with his foot where he’s locating his boxers on the floor beside the bed.

“No. You’re not leaving yet. You’re cleaning up your mess,” he orders.

Stiles’ come is still streaking the window and he doesn’t want to look at the carpet, let alone the state of his bedsheets. Derek huffs a laugh, sitting heavily on the edge of the mattress to cast his gaze about the room at the damage. Stiles spots his vest on the floor, completely shredded. So that’s how Derek got it off without him realising. The resulting situation was so great he can’t muster any annoyance over it.

“I’m gonna need to leave my window open all day. If my dad takes one breath in here, he’s going to know exactly what happened.” And with who. Even human noses could probably tell this is Derek Hale’s man musk stinking up the room. 

Derek’s eyelids flutter shut as he takes a deep breath through his nose like he’s savouring the scent of the two of them together. Derek and Stiles. Stiles and Derek. It’s going to take a while for it to sink in that that’s maybe kind of a thing now.

He slaps Derek on the chest to hide how pleased it makes him. “You sick freak.”

Derek laughs, opening his eyes to look down at him, green and gold shining in the light of the sun now starting to beam in through the windows. His smile is carefree and happy in a way Stiles doesn’t think he’s ever seen on him before. It makes Stiles’ heart do something funny in his chest, and he knows this isn’t something he can ignore. He swallows hard, nerves coiling in his gut as he prepares to speak.

“Last night, you said you wanted to show everyone that I’m yours. As in—?”

“As in, we date and go out to eat and spend time together and see where it goes from there.”

Stiles knows all about werewolf mates, knows it’s forever, knows Derek is trying to protect him from that like Stiles is too young to understand what it means and hasn’t already been fantasising about that idea for months. He doesn’t tell Derek that though. Not yet. 

Stiles cups his cheek instead, sweeping his thumb along the line of stubble against the cut of his cheekbone. He kisses him carefully, chastely, just once.

“Yeah. Okay.” It might sound like an agreement, but Stiles means it as a promise. From the look of wonder on Derek’s face, Stiles knows he understands.

**Author's Note:**

> I had just planned to chip away at this slowly when I got the idea for it earlier in the week, but then I woke up yesterday and realised today is Valentine's Day so I knuckled down to finish it. I was looking over everything else I’ve posted to ao3 and realised I’ve not written anything like this for Sterek before because smut isn’t my forte (please be kind!). I hope you enjoyed it anyway haha
> 
> Photoset [here](https://kaistrex.tumblr.com/post/643110637265960960/a-bad-case-of-the-wilds-by-kaistrex-i-could) with vague shirtlessness if you want to share it ^-^
> 
> You can find me [here](https://kaistrex.tumblr.com/) on tumblr or at my fic rec blog [Underappreciated Sterek](https://underappreciatedsterek.tumblr.com/).
> 
> Thanks for reading!


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